Hi,
Slow printing could be cause byt the following :
- File itself
- Application
- Memory of the computer
- Driver
- Connection
- Printer
- Firmware
- Ink system
- Paper type
Here are some steps for the most common
- Print an internal demo, you will find this at the printer by pressing the "?"
- Print from a USB drive using the USB port on the panel of the printer
With those 2 steps you will by pass the connection and the computer.
If you have the same problem try updating the firmware of the printer and also contact HP for further diagnose of the printer.
If you dont have the same issue, to check for a network issue
- You can try connecting the printer directly using Wireless Direct and changing the port on the printer.
If you have the same issue, try removing the actual driver and install the latest version that is on the HP site.
You will find it on the following link
HP Officejet Pro X476dw Multifunction Printer Drivers & software
I hope this helps
Best regards
Mike G